President Joe Biden fired Social Security Commissioner Andrew Saul on Friday after the Trump administration appointee reportedly refused to resign, installing Kilolo Kijakazi in his place as acting commissioner.

Kijakazi, who’d been serving as deputy commissioner for retirement and disability policy, told agency employees that Saul and Deputy Commissioner David Black, another Trump-era holdover, would be departing, according to an email obtained by CQ Roll Call.

“I thank former Commissioner Saul and Deputy Commissioner Black for their service to the public,” Kijakazi said in the email. “I am a strong believer in collaboration and [Chief of Staff] Scott Frey and I look forward to working with all of you. This is a pivotal time for the agency and the nation and I know we can overcome any challenge when we confront it together.”

The Washington Post first reported that Biden fired Saul after he refused to step down, while Black agreed to submit his resignation.

Saul and Black were each confirmed in 2019 for terms stretching to 2025, but they’d come under fire from Democrats and advocacy groups pushing for their early ouster after Biden took office in January. Critics alleged the two officials orchestrated a campaign to deny disability benefits in certain circumstances, delay pandemic relief checks for Social Security beneficiaries and eliminate telework options for agency employees.

Sen. Sherrod Brown of Ohio, the Democrat who leads the Senate Finance Committee’s Social Security subcommittee, applauded the move. Brown had called on Biden to replace Saul and Black in February.

“Social Security is the bedrock of our middle class that Americans earn and count on, and they need a Social Security Commissioner who will honor that promise to seniors, survivors, and people with disabilities now and for decades to come,” Brown said in a statement on Friday. “Instead, Andrew Saul tried to systematically dismantle Social Security as we know it from within. I look forward to working with incoming Acting Commissioner Kijakazi, who shares our commitment to protecting and expanding Social Security.”

The move drew objections on Friday from top-ranking Republicans on the panels that oversee Social Security, who described it as a politicization of the agency.

“It is disappointing that the Administration is injecting politics into the agency, given that Commissioner Saul was confirmed with bipartisan approval, worked closely with both parties in Congress, and provided smooth benefit and service delivery during the largest management challenge ever faced by the agency,” said Senate Finance Ranking Member Michael D. Crapo of Idaho and House Ways and Means Ranking Member Kevin Brady of Texas in a joint statement.

Saul and Black were each confirmed with broad bipartisan margins in 2019.

The vote to confirm Saul, on June 4, 2019, was 77-16. Democratic backers at the time included Brown, then-Finance ranking member Ron Wyden of Oregon and Charles E. Schumer of New York, the then-minority leader. Black was confirmed on Sept. 24, 2019, on a 68-26 vote. Wyden voted for Black but by then Brown and Schumer were “no” votes.

Saul, a businessman and former New York City transit official, didn’t have any experience with Social Security before taking the job, though at one point he ran the federal government’s Thrift Savings Plan for federal workers. Black was a former Social Security Administration general counsel under Democratic and Republican presidents — Barack Obama and George W. Bush, respectively — who joined the Trump transition team and then stayed on as a senior SSA adviser.

Under the law establishing Social Security, the agency’s commissioner can only be removed before his or her six-year term is up “pursuant to a finding by the President of neglect of duty or malfeasance in office.” That provision was added in 1994, though at the time the Clinton administration raised constitutional questions.

Biden’s move to fire Saul came after a recent Supreme Court decision in Collins v. Yellen, in which the court decided a requirement that the Federal Housing Finance Agency director could only be fired for cause was unconstitutional.

The Justice Department said in a memo to the White House on Thursday that it believed the president could remove the Social Security commissioner without cause in light of the FHFA ruling and another, similar decision applicable to the Consumer Financial Protection Bureau Director.

As a result of those high court rulings, the Justice memo said, the agency’s attorneys had “reexamined” the 1994 law and now “believe that the best reading of those decisions compels the conclusion that the statutory restriction on removing the Commissioner is unconstitutional. Therefore, the President may remove the Commissioner at will.”

The Washington Post reported that Saul plans to contest the White House decision in court, and that he plans to report to his old job at Social Security on Monday — remotely.